Surgery is one of the main treatments for plastic surgery patients, but postoperative pain is a big problem that has long plagued patients and surgeons. Severe pain not only causes circulatory, respiratory, digestive and urinary system dysfunction, neuroendocrine and metabolic dysfunction, but also causes mental changes such as fear, anxiety and irritability, which brings great trauma to the patient's body and mind and even affects the prognosis of the disease in severe cases. Traditional postoperative analgesia usually adopts intermittent intramuscular injection or intravenous injection of narcotic analgesics. Clinical practice has proved that this is not an ideal analgesic method. At present, the commonly used analgesic method is patient-controlled analgesia (PCA). According to the research results of patients' physiology, psychology, pharmacokinetics and pharmacodynamics, PCA is one of the most effective analgesic methods to meet patients' pain needs. Can effectively eliminate the pain after surgery, so that you can easily spend the difficult days after surgery. It is a new technique of postoperative analgesia widely used in the world. The Department of Anesthesiology in our hospital has many years of clinical experience in applying PCA pump to postoperative pain treatment, and the analgesic effect is good. In order to further improve the service quality and let patients fully understand and choose this technology, the following aspects are introduced: (1) Patient-controlled analgesia (PCA) is defined as a kind of microcomputer analgesia which is produced by the close combination of computer technology and medicine. The anesthesiologist sets the procedure and the safety limit of painkillers in advance, and the patient controls the needed painkillers intermittently through an easy-to-operate button, so as to quickly achieve the purpose of relieving or relieving pain after operation. (2)PCA special equipment: patient-controlled analgesia pump (PCA pump), its structure: ① silica gel reservoir. ② Automatic switch. ③ Manual switch. (3) route of administration: ① intravenous (PCIA): this route is associated with intravenous administration; (2) Epidural (PCIA): the passage is connected with the epidural space for administration; (3) Subcutaneous (PCIA): This route is related to subcutaneous administration. (4) Drugs used in (4)PCA: opioids: morphine, pethidine, fentanyl, etc. : bupivacaine, lidocaine, etc. Opioid drugs are mixed with local anesthetics. (5) Usage: Generally, manual switch is not needed, and the medicine can be automatically switched on and off to meet the needs of patients. However, individual patients with low pain threshold can use manual switch, and the number of times to use manual switch can be determined according to the needs of pain. (Patients can press the manual switch by themselves without the participation of clinical staff) (6) Advantages of PCA: ①PCA administration conforms to the pharmacokinetic principle of analgesic drugs, and it is easier to maintain the lowest effective analgesic concentration. ② The use of painkillers is really timely and rapid, which basically solves the individual differences of patients' demand for painkillers. ③ It is beneficial for patients to obtain the best analgesic effect at any time and under different pain intensities. ④ Relieve the adverse reactions caused by pain, such as stress, myocardial ischemia, atelectasis and delayed functional exercise. ⑤ Portable design, which is not limited by body position and space during treatment. ⑥ It is beneficial for postoperative patients to fully cooperate with treatment and early activities, promote early rehabilitation and reduce the burden on family and society. (VII) 7) Precautions in the use of 7)PCA: ① Strengthen the monitoring of blood pressure, pulse, breathing, patient's pain degree and sedation depth, carefully record and deal with problems in the use process in time. ② Explain the use of PCA pump to patients and their families before and after operation, so as to carry out patient-controlled analgesia smoothly. ③ Postoperative analgesia needs the cooperation of patients and their families. Pain is a very complicated physiological and psychological process. Patients and their families should have confidence in the anesthesiologist and actively cooperate to achieve the best postoperative analgesic effect.